In my opinion, any gadget that makes it to its 31st birthday before dying should be declared a resounding success.  This is especially true if it launches a revolution in portable music.  In this particular case, the gadget I am referring to is the Sony Cassette Walkman. 

You’ve had a great life my friend and we’re going to miss you.

On October 25, 2010, Sony Corporation officially ended production of the Sony Cassette Walkman player after a 31 year run.  First developed and produced in 1978 by Sony audio engineer Nobutoshi Kihara for Sony co-chairman Akio Morita, the portable battery operated device allowed the ability to play cassette tapes and listen to them anywhere through portable lightweight stereo headphones. 

Debut of the TPS-L2 Walkman on July 1, 1979

The first Walkman model (the TPS-L2) made its debut on July 1, 1979 in Tokyo Japan and retailed for $200.  The device features included: stereo headphones, play/rewind/fast forward/eject buttons, and volume controls.  Since the TPS-L2 introduction, Sony has sold over 220 million Cassette Walkmans.

The introduction of the Cassette Walkman became a revolutionary device that forever changed the way we enjoy our music and is arguably one of the most important consumer electronic devices ever invented.  All portable music devices that followed in its footsteps (from the Sony Discman to the  Apple iPod) owe their very existence to the Sony TPS-L2 Cassette Walkman.